2.3.10

High Grade Prostatic Intraepithelial Neoplasia (HGPIN)

High Grade Prostatic Intraepithelial Neoplasia (HGPIN):
Common questions asked about HGPIN are :
-How do we as pathologists make these diagnoses?
-What do they mean for the patient in terms of cancer risk?
-What is/are the optimal strategies for follow-up so that if cancer does eventually develop it is caught at an early, curable stage?

Pathology criteria for diagnosis of HGPIN:

-Architecturally benign acini/ducts lined by atypical cells.
-These cells show large nuclei and prominent nucleoli (cytologic features of carcinoma).
-Generally at least 10% of the luminal cells should show these features to make the diagnosis.


Diagnosis of HGPIN has been shown to be reproducible. Low grade prostatic intraepithelial neoplasia has poor reproducibility (even among experts), ill defined diagnostic criteria, and no true clinical relevance. It is for these reasons that I do not personally diagnose LGPIN.

Risk of subsequent cancer:

-In previous studies the risk of carcinoma on follow-up biopsy for a HGPIN diagnosis has been reported to be as high as 50%, however, when the data is based on series with increased case numbers, this decrease to around 25%.

-Number of cores with high grade PIN predicts risk of subsequent cancer (1 core-30%, 3 cores-40%, 4+ cores-75%).In addition, morphologic patterns of HGPIN (i.e. flat, tufted, micropapillary, cribriform) have not been shown to be predictive of subsequent carcinoma.

Follow up strategy for patients with HGPIN:

Although there have been several follow-up strategies for patients with a diagnosis of HGPIN, many recommend re-biopsy within 3-6 months. One protocol includes biopsies at 3-6 months for 2 years, followed by yearly biopsies for life.
In a recent study, recommendation was made that in the absence of other clinical indicators worrisome for cancer, men do not need a routine repeat biopsy within a year following a HGPIN diagnosis. As the natural history of HGPIN in any given patient is not known, the decision to take additional biopsies past 1 year is best made on a patient by patient basis with a frank discussion between the physician and patient.

Various studies have shown that in patients with prior diagnosis of HGPIN, cancer is often diagnosed in adjacent sites and even within the contralateral lobe. It is for this reason that when re-biopsy is performed for HGPIN sampling should be concentrated in the region of the previous HGPIN with the rest of the gland sampled so as not to miss small foci of cancer. Specimens should be meticulously labeled as to site (in addition to patient identification) and optimally no more than 2 cores should be submitted per container.

Summary:

1. HGPIN is characterized by architecturally benign glands lined by cells which are morphologically similar to prostate cancer, and is the putative precursor of prostate cancer.

2. Unlike HGPIN the diagnosis of LGPIN is not reproducible and carries no clinical significance.

3. While earlier reports described the risk of cancer following a diagnosis of HGPIN as high as 50%, more current reviews suggest that the risk may be much lower.

4. Men with a diagnosis of HGPIN (especially those with HGPIN focally) may not need re-biopsy for up to one year after initial diagnosis. Repeat biopsies should concentrate on the area of previous HGPIN, but also include sampling of the entire gland.
(Thanks to Dr.Dharam Ramnani for allowing to use the above images for this site.)
References:
1. Epstein JI, Herawi M. Prostate needle biopsies containing prostatic intraepithelial neoplasia or atypical foci suspicious for carcinoma: implications for patient care. The Journal of Urology 2006; 175: 820-834.
2. Bishara T, Ramnani DM, Epstein JI. High grade prostatic intraepithelial neoplasia on needle biopsy risk of cancer on repeat biopsy related to number of involved cores and morphologic pattern. The American Journal of Surgical Pathology 2004; 28: 629-633.
3. Bostwick DG, Qian J. High-grade prostatic intraepithelial neoplasia. Modern Pathology 2004; 17: 360-379.

2 comments:

Anshu said...

Dear Sir,
Thanks again for the post. is there any role of PSA level in diagnosis, prognostication and followup of HGPIN patients?

Dr.Prashant A.Jani M.D.FRCPC said...

Dear Anshu,

Thanks for your comment.

Whether PIN itself is associated with an elevation in serum PSA levels.?
Conflicting findings have been reported regarding the relationship between prostatic intraepithelial neoplasia (PIN) and serum prostate-specific antigen (PSA) concentration.
It has been documented in the past that in men undergoing simple prostatectomy, the finding of PIN was associated with a high PSA level.
Alexander and colleagues subsequently reported that PIN does not appear to increase PSA levels.

Of course, the establishment of PIN alone without prostatic carcinoma can only be achieved with whole-mount step-sectioning of the prostate tissue, which may explain this discrepancy.


Reference:
Urology. 1996 May;47(5):693-8.
Prostatic intraepithelial neoplasia does not appear to raise serum prostate-specific antigen concentration.
Alexander EE, Qian J, Wollan PC, Myers RP, Bostwick DG.

List of all the posts

Interesting Case

Clinical History:

53 years male,History of hypertension and tachycardia,MRI abdomen:-Left adrenal mass:- size 5.8 cm Right renal mass:- size-3.0cm Microscopic examination of the renal mass showed vascular tumor with diffuse sheets of clear cells having Fuhrman grade III nuclei. There was no evidence of necrosis within the tumor. There was no evidence of extraparenchymal invasion.
Gross examination of the left adrenal gland revealed cortically centered, solid and multinodular mass measuring 6.5 x 6.0 x 5.0 cm and weighing 122 grams. The tumor was encapsulated but showed evidence of extraparenchymal penetration. The tumor had golden brown cut surface with areas of hemorrhage and necrosis. The partial nephrectomy showed 3.0cm x 3.0cm x 3.0 cm yellow solid mass which did not invade into the perinephric adipose tissue.
Microscopically, the adrenal mass had predominant diffuse sheets and focal trabecular arrangements. The former pattern was present in about third of tumor. The cells had clear cytoplasm and round to ovoid nuclei with conspicuous nucleoli. Mitotic rate was 9/50 HPF and included atypical forms. Gross necrosis and capsular invasion were documented microscopically. There was no evidence of lymphovascular invasion. Considering the above mentioned features, a Weiss histopathologic score2 of 7/9 was applied.



Discussion:

The differential diagnosis included Renal Cell Carcinoma (RCC) with contralateral adrenal metastasis, Adrenocortical carcinoma (ACC) with contralateral renal metastasis, synchronous RCC and ACC or synchronous RCC and adrenocortical adenoma. A panel of immunohistochemical stains was performed to sort out the diagnosis. Adrenal tumor demonstrated strong Vimentin positivity and is negative for CK7, CK20, E1/AE3, EMA, Synaptophysin and S100.Renal cell carcinoma was positive for CK7, AE1/AE3, EMA (weak) and Vimentin. It was negative for CK20, Synaptophysin and S100. The difference of immunoprofile between the two tumors documented that they originated from two different primaries.

Final Diagnosis:

The diagnosis of synchronous RCC and ACC rather than metastasis influences the prognosis.

Prognosis:

The longest disease free interval after removal of contralateral adrenal metastasis was 12.1 years8 and the longest crude survival was 14.3 years. In contrast non metastazing RCC has an excellent prognosis if no metastasis developed.